Engine cooling means



Nov. 1, 1938. R. B. BEIISEL 2,134,774

ENGINE COOL ING MEANS Filed June 15, 1935 2 Sheets-Sheet l IN VEN TOR. BEBXB.BEJI5'E[ A TTORNEY Nov. 1, 1938. R. B. BEISEL ENGINE COOLING MEANSFiled June 15, 1935 2 Sheets-Sheet 2 IN V EN TOR. EEZH B5 153] B m 9 M ATTORNEY Patented Nov. 1, 1938 PATENT orr cs ENGINE COOLING MEANS Rex B.Beisel, West Hartford, Conn, assignor to United Aircraft Corporation,East 1 Hartford, Conn., acorporation of Delaware Application June 15,1935, Serial No. 26,878

' 13 Claims. (01. 123-171) This invention relates to engine coolingmeans and has particular reference to the cooling of an engine mountedupon an airplane.

One object of the invention resides in the provision of an improvedstreamlined cowling for an internal combustion engine together withmeans for improving the circulation of air past the cooling surfaces ofthe engine within said cowling.

A further object resides in the provision of a simplified and at thesame time an effective cooling arrangement for both the cylinders andtheaccessories of an air cooled airplane engine.

Other objects and advantages will appear as the description proceeds.

The accompanying drawings in which like reference numerals refer tosimilar parts throughout illustrate a suitable mechanical embodiment ofwhat is now considered to be the preferred form of the invention, thedrawings, however, are for the purpose of illustration only and are notto be considered as limiting the invention the scope of which is to bemeasured entirely by the scope of the appended claims.

In the drawings, Fig. 1 is a side elevationalv view of an airplaneshowing an improved cowl and engine cooling device constructed accordingto the idea of this invention applied thereto. Fig. 2 is a sectionalview on an enlarged scale of the cowl and cooling means illustrated inFig. 1,

i the engine being shown schematically in perspective. Fig. 3 is asectional view on an enlarged scale showing in detail the deviceillustrated in Fig. 2 for securing the nose piece of the cowl to theengine. Fig. 4- is a front elevation of a fragmentary portion of theengine and cowl shown in Fig. 2. Fig. 5 is a side elevational view on asomewhat enlarged scale of the connection between the carburetor airintake and the hot and cold air ducts particularly illustrated in Fig.2, portions being broken away to better illustrate the constructionthereof.

Fig. 6 is a sectional view taken on the line 6-6 of Fig. 5 illustratingin somewhat diagrammatic form the arrangement in plan view of the hotand cold air ducts leading to the carburetor air intake, and Fig. 7 is asectional view on an enlarged scale showing in detail the manner ofconnecting the flap supporting ring illustrated to in Fig. 2 to themembers of the engine carrying frame illustrated in the same figure.

Referring to the drawings in detail, numeralplane. While the drawingsillustrate a single engine airplane having the engine mounted upon thefront end of the fuselage. it is to be understood that the invention isnot llmitedto such an airplane but that the engine may be mounted 5 uponthe fuselage or the wing or upon any other suitable support on theairplane and that either one or aplurality of engines may be used on thesame airplane without exceeding the scope of the invention. The engineI2 drives a propeller 10 M which provides the necessary tractive forcefor the propulsion of the airplane and at the same time directs a blastof air known as the propeller slip stream rearwardly over the engine.Additional air is induced to pass over the engine 15 by the forwardmovement or flight of the airplane and this air together with thepropeller slip stream passes over the cooling surfaces of the engine andits accessoriesand carries away the excess heat developed by the engineduring 20 power operation. In order to reduce the drag or resistance ofthe engine and the fuselage to passage through the air the engine issurrounded by a streamlined cowl I6 of circular or annular cross sectionwhich 25 extends from a location adjacentto theforward end of the engineto a location adjacent to the forward end of the fuselage l0 whichforward end of the fuselage is designated as the fire wall for thereason that it comprises a fireproofpar- 30 tition [8 which divides theengine compartment of the airplane from the passenger compartment. Theengine is supported upon an engine carrying frame 20 which is detachablysecured to the forward end of the fuselage frame 22 to provide a 35rigid mounting for the engine upon the forward end of the airplanefuselage. The engine, schematically illustrated in Fig. 2, is of thetwo-row radial type having a substantially circular crankcase 24 and twobanks of radially disposed cylin- 4o ders 26 attached to the crankcaseextending outwardly thereon. Each of the cylinders is preferablyprovided with valves and valveoperating mechanism and intake and exhaustports and with finned cooling surfaces in the conventional 45 manner,however, as these details do not form a part of the present invention,'they have been omitted from the schematic illustration of the engine inorder to simplify the illustration.

As stated above the streamlined cowl l6 exo,

tends from adjacent the forward end of the engine to a location adjacentto the fire wall of the airplane thus enclosing the entire engine andits supporting frame and accessories. This cowl is preferably formed ina plurality of separate parts comprising a nose section 28, intermediatepanels 30, and a series of cowl trailing edge flaps 32. The nose piece28 is formed as a continuous annular ring and is secured to the engineby a plurality of fastening devices each comprising a pair of parallelplates or fins 34 welded or otherwise suitably secured tothe interior ofthe annular ring and lying in a radial plane. At their rearward endseach pair of fins 34 carry a block 35 having an apertured bearing memberor car 36 which lies between two apertured cars 31 formed on a bracket36 secured to a suitable projecting portion of the engine such as theforward side of one of the engine valve rocker boxes 40. A bearing pin42 extends through the apertured ears 36 and 31 of each fastening deviceto secure these members together. A plurality of these fastening devicesas illustrated in Fig. 4 are disposed in substantially equally spacedrelation surrounding the circumference of the nose piece and attached tothe engine cylinders or rockerboxes in such a manner as to provideconnections lying in different radial planes. In each one of theattaching devices the ear 36 is made less than the distance between theinner surfaces of the ears 31 on the bracket 38 to provide a smallamount of lost motion in the connection so that as the engine cylindersexpand upon heating, each bracket may move outwardly with respect to itsassociated fins in order that the engine may expand without distortingthe nose piece of the cowl. As the attaching devices lie in differentradial planes there is no tendency for the nose piece to move relativeto the engine because of the clearance allowed in the connections.

-At the rearward edge of the nose piece 28 a channel shaped ring 44 issecured to the inner surface of the nose piece in such a position thatit lies partly rearwardly of the trailing edge of the nose piece.Rearwardly of the engine a complementary ring 46 is secured to theengine supporting frame 20 by means of a suitable web construction 48preferably consisting of metal tubes 49 welded at one end to the membersof the engine supporting frame 20 and extending outwardly to the ring,the outer ends of the tubes being welded to metal pads 50 in the form ofelongated plates or strips which are in turn secured to the interior ofthe ring 46 by suitable means such as the rivets 52 as particularlyillustrated in Fig. 7. for any reason to make the ring 46 readilydetachable from the airplane detachable connecting means such as beltsor screws may be substituted for the rivets 52.

From the construction so far described, it will be observed that therings 44 and 46 provide rigid and convenient annular mounting seats atthe forward and rearward ends respectively of the engine. Between therings 44 and 46 the engine is enclosed by the intermediate portion ofthe cowling, this intermediate portion being made up of four separatelongitudinal panels 30 each of which may be detached without disturbingthe others in order to provide quick and convenient access to theengine.

In order to facilitate the cooling of the engine a system of pressurebafiles 56 is provided extending between the various engine cylinders torestrict the fiow of air through the engine to areas closely adjacent tothe cooling surfaces, the baffles being extended outwardly to theinterior surface of the cowl as indicated at 54 in Fig. 2. Thisconstruction provides a cooling system known In case, however, it isdesired.

as the pressure baflle system particularly described in applicationSerial No. 705,094 of Rex B. Beisel, and Albert MacClain, for Airregulating means, filed January 3, 1934. In accordance with theprinciples of this method of cooling, the air ahead of the pressurebaffles 56 is maintained at a static pressure having a higher value thanthe air at the rear of such pressure baffles to increase the speed ofthe air stream flowing past the cooling surfaces of the engine tothereby more effectively remove the excess heat from the engine. Such asystem of cooling, however, places the accessories mounted upon the rearsection of the engine in an atmophere in which the air pressure isrelatively low and the temperature relatively high and which does notreadily absorb the heat from these accessories. It has previously beenthe practice to cover the rear section of the engine and all of theaccessories in a cowl, known as a wrapper cowl and in necessary cases toprovide air vents for ventilating the interior of this wrapper cowl tocarry away the excess heat of the engine accessories. In the presentarrangement, however, it has been found that this wrapper cowl may beentirely eliminated, thus considerably reducing the weight of the powerplant and at the same time rendering the engine accessories much moreeasily accessible to inspection and repair as, in the present device,these accessories may be exposed by simply removing one of the panels 30of the intermediate section of the outer cowl without the necessity ofremoving any portion of an inner or wrapper cowl. However, as it maystill be necessary in some cases to provide additional cooling for theengine accessories, my improved cowl is provided with a ventilatingmeans in the form of a box-like channel 56 secured to the inner side ofone of the panels of the intermediate portion of the cowl and having anopening 60 forward of the pressure baffles 56 so that air from the highpressure area in front of the pressure baffles may flow into thischannel and be directed by suitable means, suchas the tube 62, to thoseengine accessories, such as the magneto 64 which may require additionalcooling. While only one such air conducting channel is illustrated, itis to be understood that if desired additional air conducting channelsmay be provided. The drawings also illustrate a similar air conductingchannel 65 provided on the lower panel of the intermediate section ofthe cowl leading from the forward side of the pressure bafiles -56 tothe air intake 66 of the carburetor 68. Besides providing convenient airpassages for carrying necessary quantities of air from the forward sideto the rearward side of the pressure bafiles, these box channelstructures serve to stiffen the panels of the intermediate portion ofthe cowl and thus render these panels rigid and durable without theaddition of the unnecessary weight.

When the inner or wrapper cowl mentioned above is used it is placed atits forward end within the exhaust collector rings 10 to direct the airheated by the exhaust gases away from the engine accessories. Withoutthis inner or wrapper cowl it has been found desirable to enclose theexhaust collector rings in a shroud or muff 12 to prevent the exhaustgases from raising the temperature of the air surrounding the engineaccessories to an undesirably high value. Each muff or shroud T2 besidesenclosing the collector ring itself is provided with extensions 14 whichenclose the major portions of exhaust stacks 16. All of the extensions14 terminate in a plane immediately rearwardly of the pressure bafiles56 so that the cooling air flowing between the pressure baliles and theengine cylinders is blown into the open ends of the extension [4creating an air stream between the extensions and the exhaust stacks I6and the shrouds 12 and the exhaust collector rings 10 to continuouslyremove the heat radiated by the exhaust stacks and collector rings. Eachshroud I2 is provided at its lower end with a duct 18 leading toopenings 19 in the air duct 65 adjacent to the air intake 66 of thecarburetor 68 and to a second opening 80 venting to the atmospherc, thetwo openings being controlled by a pivoted triangular valve 82 so thatthe heated air flowing through the exhaust shroud 12 may be utilized tofurnish additional warm air to the carburetor air intake when this isdesirable or may be vented to the atmosphere along with the exhaustgases. The main function of the exhaust shroud, however, is to removethe exhaust heated air from the interior of the cowl to therebyfacilitate the cooling of the accessories mounted upon the rear sectionof the engine. A spring closed door 8! is positioned over the opening 86and through the opening 80 to the atmosphere.

moved to open position by a tongue 83 when the valve 82 is moved to ventthe exhaust heated air outside of the cowl.

The valve 82 has a shape substantially resembling the diagonal half ofan oblong box structure and has a complete top wall and a side walladjacent to the carburetor air inlet 65 and has diagonal end walls. Asshown in Fig. 6, this valve structure extends entirely across thecarburetor air inlet opening from one shroud opening 18 to the other.When in the full line position illustrated in Fig. 5, the valve is sopositioned that its top wall extends across the tops of the two shroudopenings I9 and its side wall extends across the vertical sides of theshroud openings adjacent to the carburetor air intake. The diagonal endwalls cover a portion of the shroud opening but leave a portion,substantially one-half, of such shroud openings uncovered. When in thefull line position shown in Fig. 5, air from the shrouds flows to theinterior of the box-shaped valve member and from this valve memberdownwardly The openings 19 are never closed since it is necessary tomaintain at least a portion of these openings uncovered to permit air tocirculate. through the shroud member to cool the exhaust stacks andcollector ring, but when positioned as illustrated in full lines in Fig.5, the valve member functions to divert the hot air from the shroud tothe atmosphere through the opening instead of intothe carburetor airintake, the carburetor air in this case being drawn through the airinlet opening 65 into the carburetor intake 66. When the valve is in thedotted line position illustrated in Fig. 5, the openings 19 arecompletely uncovered and the passage from the carburetor air inlet 65 tothe air intake 66 is substantially closed by the top and side wallmembers of the valve. When the valve is moved to the dotted lineposition by suitable means such as the manually operable,

push and pull cable 85, the flap BI is closed so that the hot air willpass from the shrouds through the opening 19 directly into the carburetor air intake 66.

The ring 46 carries at its rear edge a series of trailing edge flaps 32,the flaps being hinged at their forward ends to the rear edge of thering by hinges as indicated at 84 and extend from the ring 46 to theplane of the fire wall l8. From an inspection of Fig. 2 it will beobserved that this improved engine cooling construction provides anunobstructed gill opening between the fire wall l8 and the ring 46 sothat the air flowing through the cowl may be easily and rapidly ventedfrom the interior thereof without encountering the re sistance oiferedby an internal cowl shoulder, and that, as the area within this gillopening is not obstructed by an inner or wrapper cowl, the air stream isnot divided but air blowing from any part of the engine may be ventedfrom any portion of the gill opening. Each of the flaps 32 preferablycomprises a substantially rectangular sheet metal member having securedto the underside thereof a box-like reinforcing member 86 also formed ofsheet metal, to render the flap rigid against twisting and bendingforces induced by the air pressure on the flaps when they are in theextended position as indicated by the dotted lines at the bottom of Fig.2.

Suitable means are provided for extending and retracting the flaps inorder to vary the gill opening between the ring 36 and the fire wall l8such suitable'fiap operating means being illustrated and described indetail in application Serial No. 26,631, filed June 14, 1935 by James M.Shoemaker, for Engine cooling means for internal combustion engines.Such a flap operating mechanism may comprise a plurality of units inwhich each unit consists of a substantially triangular lever member 88hinged at its base to the ring 46 by two widely separated hinges andconnected at its free end to each of two adjoining flaps 32 by means ofpivoted link members 96 so that movement transmitted to one flap orhinged lever member will be transmitted through the pivoted links andthe hinged lever members'to all of the other flaps in the series. Theflaps are also preferably overlapped at their adjacent edges to avoidgaps between adjacent flaps when extended and, in some cases, assist thelever members and links in maintaining the flaps in alignment so thatall of the flaps will move consecutively and to the same degree ofmovement when a moving force is applied to one of the flaps. A manuallyoperable device such as the screw shaft 92 and screw threaded stud 94may be applied to one of the hinged lever members 88 so that manualrotation of the shaft 92 will move the stud 94 to extend or retract theflaps.

When the flaps are extended as indicated in dotted lines at the bottomof Fig. 2 air flowing past the cowling creates a low pressure areabetween the free ends of the flaps and the fire wall l8, thus creating apartial vacuum in the interior portion of the cowl rearward of thepressure baffles 56 thereby increasing the pressure differential uponthe opposite sides of the pressure bafiles and increasing the speed ofthe cooling air streams flowing between the pressure baflles and thecooling surfaces of the engine. The present invention materiallyincreases this cooling effect by increasing the facility with which theair is vented or exhausted from the interior portion of the cowlrearward of the pressure baffles.

From the above description it will be observed that the improved enginecooling means herein illustrated and described provides a constructionin which the nose section of the cowl is rigidly attached to the engine,the intermediate portion of the cowl is divided into four panels each ofwhich is readily separately detachable and in which the trailing edgeflaps, forming an integral part of the improved cooling system, arehinged to a ring which is rigidly secured to a fixed portion of theairplane and does not depend upon any portion of the cowl for itssupport, and that the construction further provides improved cooling ofthe engine by eliminating the inner or wrapper cowl or the engineaccessories and provides the exhaust collector ring with a shroud forventing the heat radiated by the exhaust gases directly to the exteriorof the cowl.

While a particular mechanical embodiment of the idea of my invention isillustrated and described herein, it is to be understood that theinvention is not limited to the particular embodiment so illustrated anddescribed, but that such changes in the size, shape and arrangement ofparts may be resorted to as come within the scope of, the sub-joinedclaims.

Having now described the invention so that others skilled in the art mayclearly understand the same, what it is desired to secure by LettersPatent is as follows:

What I claim is:

1. In a vehicle having a fuselage, an engine compartment, and an enginein said engine compartment, cooling means for said engine comprising, anopen ended cowl surrounding said engine and having its trailing edgespaced from the forward edge of said fuselage to form a gill opening forthe exit of engine cooling air, a fuselage carried support for thetrailing edge of said cowl, a series of flaps hinged to said support andextending across said gill opening adjustable to control the amount ofengine cooling air vented through said gill opening, and manuallyactuatable means for adjusting said fiaps.

2. In a vehicle having a fuselage provided at its front end with a firewall, an engine compartment forward of said fire wall, an open endedcowl surrounding said engine compartment and having its trailing edgespaced from said fire wall to provide a gill opening for the exit of.engine cooling air, a support at the trailing edge of said cowl, aseries of adjustable flaps hinged to said support and extending to saidfire wall to control the extent of said gill opening, and means foradjusting said flaps.

3i In a vehicle, an engine compartment, a fire wall atthe rear of saidengine compartment, an open ended cowl surrounding said enginecompartment and having its trailing edge spaced from said fire wall toprovide a gill opening for the exit of engine cooling air, a support atthe trailing edge of said cowl, a series of adjustable flaps hinged tosaid support and extending across said gill opening to said fire wall,and means for adjusting said flaps.

4. In a vehicle, an engine compartment, an engine in said compartment, aplurality of. air baflles mounted on said engine and forming with saidengine an air pressure partition dividing said engine compartment into aforward portion of relatively high air pressure and a rear portion ofrelatively low air pressure, engine accessories exposed to therelatively low pressure air in said rear portion, an exhaust collectorring in said rear portion, and a shroud for said exhaust collector ringfor carrying the heat radiated by exhaust gases to the exterior of saidrear portion of said engine compartment and away from said engineaccessories.

5. In a vehicle, an engine compartment, an engine in said compartment, aplurality of air batlles mounted on said engine and forming with saidengine an air pressure partition dividing said engine compartment into aforward portion of. relatively high air pressure and a rear portion ofrelatively low air pressure, engine accessories exposed to the lowpressure air in said rear portion,

an exhaust collector ring and exhaust stacks in said rear portion, and ashroud surrounding said exhaust collector ring and portions of saidstacks having said stack surrounding portions terminating in thevicinity of said air baflles whereby air flowing through restrictedopenings in said air pressure partition will flow through the spacebetween said shroud and said exhaust collector ring and said exhauststacks to carry the heat radiated by the exhaust gases out of said rearportion of said engine compartment and away from said engineaccessories.

6. In a vehicle, an engine compartment, a cowl surrounding said enginecompartment, an engine having a carburetor and an exhaust collector ringand exhaust stacks in said compartment, a shroud surrounding saidexhaust collector ring and portions of said exhaust stacks, said stacksurrounding portions being open to receive air from the cooling airstream flowing past said engine, an air duct having an opening at oneend connected with said shroud for venting the air flowing therethroughoutside of said cowl and a second opening connected with the air intakeof said carburetor, and a valve opposite said openings operable toselectively direct the air flowing through said shroud through one orthe other of said openings.

7. In a vehicle, an engine compartment, an engine and an engine carryingframe in said engine compartment, a streamlined cowl enclosing saidengine compartment, a supporting ring for the trailing edge of said cowlsupported on said engine carrying frame, a series of cowl trailing edgeflaps hinged to and carried by said ring, and flaps actuating mechanismalso carried by said ring.

8. In a vehicle, an engine compartment, an engine and an engine carryingframe in said compartment, a streamlined cowl surrounding said enginecompartment, a series of cowl trailing edge flaps, a ring for supportingthe trailing edge of said cowl and carrying said flaps, and means forsupporting said ring on said engine carrying frame, said meanscomprising a plurality of strut members secured at one end to themembers of. said engine carrying frame and extending outwardly to form aweb between said frame and said ring, and a ring carrying pad secured tothe outer end of each strut and to said ring.

9. In a vehicle, an engine compartment, an engine and an engine carryingframe in said compartment, a streamlined cowl surrounding said enginecompartment, said cowl having a front section rigidly secured to saidengine, a ring carried by the front section of said cowl and extendingbeyond the trailing edge thereof, a second ring supported on said enginecarrying frame, a plurality of intermediate cowl section panels securedat their opposite ends to said rings, and a series of cowl trailing edgeflaps carried by said engine carrying frame supported ring.

10. In a vehicle, an engine compartment, an engine in said compartment,a streamlined cowl enclosing said engine compartment said cowl having aseparate front section and means for supporting said front section onsaid engine said means comprising, a plurality of brackets secured tosaid engine at spaced intervals around the outer circumference thereof,a pair of spaced radially disposed apertured ears on each bracket, aplurality of radial fins secured to the inner surface of the frontsection of said cowl and a plurality of lugs secured to said fins eachof said lugs having an apertured portion disposed between one pair ofsaid apertured bracket ears the aper tured portion of said lug having adimension less than the space between said ears to provide a lost motionconnection for the-expansion or contraction of said engine, and abearing pin extending through each pair of apertured ears and theassociated lug portion.

11. Inc. vehicle an engine compartment an engine in said compartment astreamlined cowl enclosing said engine compartment, said cowl having afront section rigidly secured to said engine, an intermediate sectionand a rear section, and a supporting ring of channel section rigidlysecured to said front section and extending beyond the trailing edgethereof to support the leading edge of the intermediate section of saidcowl.

12. Engine cooling means comprising, in combination with an engineadapted to be moved relative to the surrounding air, an enclosure forsaid engine having cooling air inlet and outlet openings, bafliesadjacent to said engine to constitute with said engine a partition insaid enclosure providing in said enclosure two portions one'connectedwith the air entrance opening and the other with the air exit opening,said partition stringently restricting the flow of cooling air from saidair entrance opening connected portion to said air exit openingconnected portion to provide a high velocity flow inducing pressure dropbetween said portions of the engine enclosure, an engine accessory in aportion of said enclosure filled with air at a pressure below the airpressure in said air entrance opening connected portion, and a blasttube extending from saidair entrance opening connected portion to saidaccessory containing portion operative to conduct air from said airentrance opening connected portion and direct said air as a cooling airblast to said accessory.

13. Engine cooling means comprising, in combination with an engineadapted to be moved relative to the surrounding air, an enclosure forsaid engine having cooling air inlet and outlet openings, bafflesadjacent to said engine to constitute with said engine a partition insaid enclosure providing in said enclosure two portions one connectedwith the air entrance opening and the other with the air exit opening,said partition stringently restricting the flow of cooling air from saidair entrance opening connected portion to said air exit openingconnected portion to provide a high velocity flow inducing pressure dropbetween said portions of the engine enclosure, a carburetor in a portionof said enclosure filled with air at a pressure below the air pressurein said air entrance connected portion, and a carburetor air intake ductextending from said air entrance opening connectedportion to the intakeof said carburetor.

REX B. BEISEL.

